The present invention relates to cutting tools and more particularly to a cutting tool provided with a removable indexable cutting insert.
It is known in the art of cutting tools for effecting cutting operations such as milling, turning, boring, broaching and the like, to provide a holder with a cutting insert which is either fixedly secured to the tool holder by brazing, or which is removably mounted in a cutting position on the tool holder by a mechanical fastening mechanism.
Diverse mechanical attachment devices have been provided in the past for removably mounting interchangeable throw-away cutting inserts, made of a metallic carbide or ceramic, for example, on a holder. Such devices may be in the form of a clamp, an eccentric pin or a screw passed through a mounting aperture in the insert. Clamps are arranged to hold the insert in a pocket formed in the holder, by applying vertically directed clamping force urging the bottom surface of the insert in engagement with the bottom of a pocket formed in the tool holder, with one, or more, edge or side surface of the insert in engagement with one, or more, sidewall of the pocket. Clamping pins rely principally on wedging engagement or frictional engagement between two consecutive side surfaces of the insert and corresponding consecutive sidewalls of the tool holder pocket, with the resultant of the forces acting on the cutting insert during a cutting operation being relied upon for applying the bottom face of the insert in engagement with the bottom of the pocket.
Most of the cutting insert clamping mechanisms or wedging mechanisms of the prior art are only effective to a certain degree, some comprise many parts requiring many machining operations to be effected on the tool holder, and many fall short of providing positive locking of a cutting insert to a tool holder, while permitting easy removal of the insert for indexing a fresh cutting edge, or for replacing a worn cutting insert by a new one.